This is exactly why I like a 4ft perimeter of mulch around my beds.

Because wood ash will affect the pH I would avoid that.

Try cardboard or layers (>3) of newspaper with some wood chips mulch on it to hold it in place.

"Grass is a perennial weed that invades my vegetable garden."

If you don't want to dig it up, it's not going to want to leave. It's either a lot of work now digging it up, or continuous work forever pulling it. Now, Roundup works on Bermuda, and doesn't leave long-lasting residues. If your soil is alkaline, wood ash is toxic waste. In any case, I doubt wood ash would discourage Bermuda, which is highly tolerant of all kinds of stuff, including toxic waste.

No, neither wood ash nor sawdust will stop the Burmuda Grass. You need a physical barrier, such as newspaper or cardboard. If there are gaps in the newspaper and/or cardboard, it will sneak through, so it must be layered when you put it down.

I wouldn't recommend poison either. People seem to poison and poison and poison their Burmuda Grass. I mean the same people, in the same place.

I like a combination of removal by hand and the newspaper technique. It is nice when you finally start to see that the stuff is succumbing, rather than loving every thing you put in its way.

+1

Is it true that Round Up is the same thing used in Vietnam aka Agent Orange?

No, Agent Orange was 2,4-D. Roundup is Glyphosate. Not great stuff to take a bath in, or drink a tumbler full, but it's pretty innocuous when used in the very small quantities that most applications require.

Soil solarization. I've used it 3 times and it works really well for bermuda. I have some articles about it and I can post tomorrow morning but just Google "soil solarization". It works.

Re solarization, I tried that. Does a dandy job on the Bermuda leaves. Brown and crisp. Doesn't do anything to the roots. You leave the roots, and you leave the problem.

It worked for me, killed the roots. I did have to Round-Up a few stragglers but mostly it just plain worked. Just sayin'....

Well, stands of Bermuda are pretty much all interconnected in the root system, and Roundup is absorbed by the foliage and kills the roots. So I'm guessing that putting Roundup on those few stragglers did the real job. That's the point. Had you not done that, you would have eventually ended up with LOTS more stragglers. It doesn't take much Roundup to do the job. Certainly not a "copious amount"

Do you have sides on your raised beds? My beds are mounded so I can dig a slanted trench around the bed. It doesn't do a lot to stop creeping jenny but the runner roots of quack grass seem reluctant to go into the air space. Plus, the mower can get closer to the bed. Keep it cut seems to reduce how quickly it wants to send out runners. I also use a thick layer of newspapers covered with grass clippings. Depending on what is planted in the bed, a heavy straw mulch is helpful in reducing weeds. This works for me with garlic and potato beds. Garlic grows up through the straw.

If you have to weed, I find a Cape Cod weeder or similar works best. As you tug on the weed and dig with the weed along the root, you can get more of the root without it snapping off to regrow. I've seen some roots over 2 feet long. Paths in my high tunnel are thick layers of newspaper covered with grass clippings. Does a pretty good job of staying mostly weed free since the entire area of beds under the high tunnel was built using the lasagna method.

That said, I still do a lot of weeding early in the season, mostly getting the beds back into shape. Black plastic goes over the squash bed to kill creeping jenny that invades the bed after the squash starts running. It's easier to fork out after it looks dead.

Thank you everyone for your comments! I'll skip the wood ash! I didn't realize it could be toxic waste!

I thought the sawdust was a good idea because I figured it would tie up so much nitrogen in the soil that the Bermuda would grow very slowly and wouldn't have as much vigor to invade my bed.

I am still really leery about spraying glyphosphate because this bed has blueberries in it, so it's not like I can wait until the end of the season when everything's gone and spray then. I mean, I've seen what even a little glyphosphate drift can do to tomatoes, and I'd hate to do that to a perennial bush. Of course I'd be careful, but...it only takes a little bit of wind the wrong way, and you've got a blueberry bush that will waste a season just getting over the glyphosphate damage.

If anyone thinks a thick layer of sawdust will slow it down, I'll apply a layer of appliance-type cardboard and mulch on top of that.

I live in the South, and straw is surprisingly hard to come by, but I can get copious amounts of pine straw and/or plain wood mulch. Would either of those be better, or doesn't it matter what you mulch with overtop of the heavy cardboard?

Pine straw is good and I think it does last a bit longer too.

IF you are growing blueberries the last thing you want is wood ash to increase the soil pH or anything that will tie up nitrogen unless there is a reason for that?

Keep in mind that roots will also be growing outside the boundaries of the bed.

OK, you've given another clue. I said that in alkaline soil wood ash was like toxic waste. That's because wood ash strongly rises pH. But you say you have blueberries. If you have blueberries, you sure don't have alkaline soil! In that case, wood ash can be a good fertilizer if you don't overuse it, though I don't think it would hurt Bermuda grass, and might actually help it.

Good to be careful about glyphosate and blueberries. That's smart. But at least Roundup comes in bottles with highly directional sprayers. If you point the stuff one way, it won't end up going the other way. Also, you shouldn't need to use a lot.

Roundup actually works well on Bermuda, BUT not on dormant Bermuda. That is, the plants have to be green and active. If they aren't, the herbicide won't be absorbed and carried to the roots. This is well known to people who have Bermuda lawns that are getting infested with other weeds. You can apply Roundup to get rid of those weeds, but only if the Bermuda is completely dormant. As in, not a bit of green. If there is green Bermuda there when you apply Roundup, you'll kill your lawn.

Many times Roundup will appear to kill bermuda, but the rhyzomes survive. It is hard to kill Bermuda in the spring of the year because all the sugars from the plant are moving out, away from the roots. In the fall of the year the sugars are moving towards the roots and then it can kill the Bermuda. I have no problem with Roundup but it works better on other grasses, not very well with Bermuda. Some of the premixed formulations may have another chemical to help control Bermuda.

Well, indeed 2,4-D is more effective on Bermuda than glyphosate, but it's pretty nasty stuff. Now we're talkin' Agent Orange. Environmental lifetime of that is significantly longer than glyphosate, so you won't be planting in that bed for a while if you use it.

Let's face it. The best way to get rid of Bermuda is to dig it up and emplace a deep root shield.

I think the difference with my experience and yours is the rate of roundup. Farmers put out 1 quart of roundup with 15 gallons of water per acre. At that rate it will kill other annual grasses but will not kill the bermuda grass.

Agent orange was a mixture of 2,4D and 2,4,5T, It worked real well on killing brush but had several bad side effects. Ranchers use to spray that mixture to kill mesquite trees. Nothing has worked as well since. 2,4D will kill seedling grass but usually will not hurt established grass stands. People even spray it on tender grasses such as bahia and carpet grass.

And I do agree, the best way to get rid of bermuda is to dig it up and dispose of the runners. Just turning it under, even several inches, will only make it harder to control later. It doesn't grow under a buried barrier but will grow if bermuda grass itself is buried.

So what I'm hearing is dig it up, glyphosphate or a barrier.

The best of those choices to me is a barrier. Do you all think metal edging, installed on the outside of the bed, but flush with the wood will work to prevent further encroachment?

I would remove all the Bermuda a couple of inches away from the bed and then install the metal barrier in the ground. Then just use a grass trimmer around the metal barrier to keep the Bermuda from growing over the barrier. The Bermuda already in the bed will need to be pulled out by hand. Once you stop the Bermuda from growing under the barrier and pull up what is in the bed, there will only be Bermuda coming up from seed which will be easy to pull up. It may take a while to get all the runner out of the bed if they were buried. Only a small piece of Bermuda will make another runner.

I like to use space as a barrier. In my case 4ft but you can use 3, 2, or 1 foot if that fits better.

Keep in mind growing anything right up to your bed frames only allows them to steal nutrients and moisture from your desired plants as they send their root tips out beyond the bed frame in search of their food.

If the barrier is underground, just make sure it is deep. Less than 8-inches or so and the Bermuda will just sneak under it. Cheap plastic or segmented cedar rolled edging isn't that wide, and even edging stones aren't usually deep enough. Exactly right that Bermuda seeds will still spill on top of your bed, but those plants are easily removed.

Another reason for a 4ft space barrier - using a mower or weed trimmer near and around growing beds (esp when growing right up to the frame) will serve to scatter weed seeds throughout.

Bermuda grass will go runners 10 to 15 foot long in a year. The space barrier would quickly become covered in Bermuda and then go into the bed.

I guess you don't think it would be practical to insert a border at the outer edge of the space barrier? Or at both edges if there are beds on both sides?

I have a 20 to 25 foot gravel/caliche driveway. Bermuda grows in between where the tires are. The roadbed is at least a foot deep. I spray roundup once a year on the driveway but the Bermuda is still there. No level border will contain Bermuda. Only a border that is vertical. If the vertical border at the edge of the barrier keeps out the Bermuda from the barrier, why not just use the border to begin with. A space barrier would work for bunch grass, but not the sod forming grasses that spread several feet in a year.

'Let's face it. The best way to get rid of Bermuda is to dig it up and emplace a deep root shield.'

I agree with that statement.

Bermuda Grass has rhizomes that travel deeply. If you want a Bermuda lawn next to the vegetable garden, then a strong barrier might be in order. This barrier would have to be deep. I suppose you would need it bent at the top for safety reasons.

I don't want one single piece of Bermuda Grass on my place so am using both the newspaper/cardboard technique and removal by hand (as not all places can be layered with newspaper and then mulched over).

I am not in favour in using poison on anything, but if it is used on Bermuda Grass, then it should be applied during Autumn/Fall.

The grass should be growing as healthily as it can so that it takes up as much of the poison as it can. And a surfactant can be used (such as dish washing liquid) to encourage the poison to adhere to the grass.

But you stated that you were not keen on poisoning it. And even if you poison the stuff in the vegetable garden, you still need to put in a barrier to prevent the Bermuda from the lawn creeping both underground and over the ground into the Vegetable bed.

I think the OP said they didn't want to use "copious amounts" of poisons. It just takes a few drops of glyphosate on a Bermuda stem to kill it down to the roots. I have a garden bed that is adjacent to a stand of Bermuda, and this seems to work well. Sure, new rhizomes will eventually migrate into the bed from unpoisoned roots, so it's a continual process. No poison will absolutely eradicate it forever. Of course, no digging will absolutely eradicate it from a particular bed forever either, unless there is a below-ground shield.

If bermuda grass is the only weed you have then I suppose just a vertical barrier may work. Tho that will not keep it from growing in the walkways.

For me, I don't want bermuda grass or any other weeds growing near my beds or in my walkways if possible. So for me it's a combination of prevention and constant maintenance.

I also avoid the use of most chemicals near or on anything I will put in my mouth.

Right now I have some bugs eating some leaves and things don't look picture perfect but they are not bothering the fruit - so be it. I use dish or hand soap mixed with rainwater in a spray bottle.

"Your garden is the only place you will know just what chemicals were sprayed on things". ~ Gumby

WANT TO KILL BERMUDA GRASS? A few options may work, but not for everyone.

I have wood mulch paths around my raised beds. When Bermuda grass sends shoots through and into the path, I give that shoot a squirt of Roundup. My yard is Fescue, but there is still lingering Bermuda, so I'll take any chance I can to kill any that wants to reach into my gardens. Eventually I hope to get rid of all of it, as it really is contrary to anyone that wants garden beds rather than just wall to wall grass.

gumby that link is good if you want to use poison but is hopeless if you don't, because that's all it talks about.

It's a good point you made about any grass pathways through the vegetable bed. These would need barriers down them as well. Altogether a great deal of work to get them there. Better to choose a different species of grass for the lawn.

That link is a really good one, but is strangely incomplete. There are ten "lessons" listed of which only four seem to be available. Where are lessons 5-10?

As to the link not referring to solutions that don't use herbicides, unless you dig it all up, I think the message is that eradicating Bermuda is indeed hopeless without using herbicides.

<gumby that link is good if you want to use poison but is hopeless if you don't, because that's all it talks about.> I posted it as an fyi for those that do. I don't.

I want to elevate my 4x4 beds to keep grass out. I just need to figure out what to use as a base platform. Cinder block elevation and concrete board bottoms? 2x6 wood bottoms? Any ideas? Plywood would rot fast. Anyone done something like this?

Reading above there are other ways to keep grass out - mainly more space between the grass and the bed.

A friend of mine decided that he wanted to "build up" too so he installed a raised bed (not elevated over the ground but on the ground). He was trying to defeat bermuda grass too but made a huge mistake thinking that it could be smothered to death by an extra foot of soil on top. Naturally this does not work on BG. Told him that before installing his raised bed that he should have dug very deeply in the area, not just to cultivate the site but to pull out every BG root before filling in the raised bed. Sometimes easy is not peasy.